well system. added a new sprinkler to cover new plants. system does not produce enough pressure to drive heads in this zone. blocked it off and now all remaining are fine. need water in last head. how to accomplish? 1" PVC underground. my thought was to reduce PVC to 1/2" to increase pressure but everything i read says this creates friction thereby reducing pressure even more. other 3 zones fine as well as this one as long as i have the last head blocked.
